why is a HTML entity enlarging it's father HTML element?

I made a simple 2 tier navigation menu with only one dropdown menu. I've added a 🢓 entity to that 2 tier dropdown menu and it's enlarging its containing element. There's no margin/padding/border that causes this problem. Is there a way to fix that without removing the HTML entity?

nav#menu ul {list-style-type: none; position: relative; padding: 0;}
nav#menu ul li {float: left;width: 190px;}
nav#menu ul li a {
    text-decoration: none;
    display: block;
    text-align: center;
    padding: 1rem 0;
    background-color: cornflowerblue;
    color: white;
    border-right: 2px solid white;
    border-top: 2px solid white;
    font-family: sans-serif;
    font-weight: bold;
}
/* appears when floating */
nav#menu ul ul {
    display: none;
    position: absolute;
    top: 100%;
}
nav#menu ul ul li a{
    display: block;
    text-decoration: none;
    text-align: center;
    background-color: cornflowerblue;
    color: white;
    padding: 1rem 0;
    font-family: sans-serif;
    font-weight: bold;
}
nav#menu ul ul li {
    float: none;
    width: 190px;
    padding: 0;
}
nav#menu ul li:hover > ul {
    display: block;
}
nav#menu > ul::after {
    content: "";
    display: block;
    clear: both;
}
.level2 li {
    border-top: 2px solid white;
}
nav#menu a:hover, nav#menu a:focus{background-color:rgb(45, 114, 241);}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="styles.css">
    <title>Navigation Menu</title>
</head>
<body>
    <nav id="menu">
        <ul>
          <li><a href="#">Home</a></li>
          <li><a href="#">Menu &#129171;</a>
            <ul class="level2">
              <li><a href="#">One</a></li>
              <li><a href="#">Two</a></li>
              <li><a href="#">Three</a></li>
            </ul>
          </li>
          <li><a href="#">Products</a></li>
          <li><a href="#">Help</a></li>
          <li class="lastitem"><a href="#">About</a></li>
        </ul>
      </nav>
</body>
</html>

Solution

Yes, there is. The enlargement is caused by the glyph for the character entity being drawn from a different font, with different font metrics.

What I recommend doing is putting the entity reference in a span, and giving the span a minimal line-height. Something like this:

nav#menu ul {list-style-type: none; position: relative; padding: 0;}
nav#menu ul li {float: left;width: 190px;}
nav#menu ul li a {
    text-decoration: none;
    display: block;
    text-align: center;
    padding: 1rem 0;
    background-color: cornflowerblue;
    color: white;
    border-right: 2px solid white;
    border-top: 2px solid white;
    font-family: sans-serif;
    font-weight: bold;
}
nav#menu ul li a span { /* <== the added rule */
  line-height:1px;
}
/* appears when floating */
nav#menu ul ul {
    display: none;
    position: absolute;
    top: 100%;
}
nav#menu ul ul li a{
    display: block;
    text-decoration: none;
    text-align: center;
    background-color: cornflowerblue;
    color: white;
    padding: 1rem 0;
    font-family: sans-serif;
    font-weight: bold;
}
nav#menu ul ul li {
    float: none;
    width: 190px;
    padding: 0;
}
nav#menu ul li:hover > ul {
    display: block;
}
nav#menu > ul::after {
    content: "";
    display: block;
    clear: both;
}
.level2 li {
    border-top: 2px solid white;
}
nav#menu a:hover, nav#menu a:focus{background-color:rgb(45, 114, 241);}

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="styles.css">
    <title>Navigation Menu</title>
</head>
<body>
    <nav id="menu">
        <ul>
          <li><a href="#">Home</a></li>
          <li><a href="#">Menu <span>&#129171;</span></a>
            <ul class="level2">
              <li><a href="#">One</a></li>
              <li><a href="#">Two</a></li>
              <li><a href="#">Three</a></li>
            </ul>
          </li>
          <li><a href="#">Products</a></li>
          <li><a href="#">Help</a></li>
          <li class="lastitem"><a href="#">About</a></li>
        </ul>
      </nav>
</body>
</html>